The compounds of the formula [I] are novel compounds which have been disclosed for the first time in EP-A-398 692 in the name of the present assignee, and they are considered to be remarkably useful compounds as agricultural fungicides having excellent fungicidal activities against microorganisms such as Piricularia oryzae, Pellicularia sasakii, Pseudoperonospora cubensis and the like.
In the above application, the compounds of the formula [I] are produced by several routes. However, at this time, the present inventors have found other novel synthetic routes for producing the compounds of the formula [I] which are more economical with minimum by-products.